Counter(): add 'one thousand' param. (#657)

* Counter(): add 'one thousand' param.

Needed for https://github.com/google/benchmark/pull/654

Custom user counters are quite custom. It is not guaranteed
that the user *always* expects for these to have 1k == 1000.
If the counter represents bytes/memory/etc, 1k should be 1024.

Some bikeshedding points:
1. Is this sufficient, or do we really want to go full on
   into custom types with names?
   I think just the '1000' is sufficient for now.
2. Should there be a helper benchmark::Counter::Counter{1000,1024}()
   static 'constructor' functions, since these two, by far,
   will be the most used?
3. In the future, we should be somehow encoding this info into JSON.

* Counter(): use std::pair<> to represent 'one thousand'

* Counter(): just use a new enum with two values 1000 vs 1024.

Simpler is better. If someone comes up with a real reason
to need something more advanced, it can be added later on.

* Counter: just store the 1000 or 1024 in the One_K values directly

* Counter: s/One_K/OneK/

1 files changed, 153 insertions, 0 deletions

diff --git a/test/user_counters_thousands_test.cc b/test/user_counters_thousands_test.cc
new file mode 100644
index 0000000..6e02829
--- /dev/null
+++ b/test/user_counters_thousands_test.cc
@@ -0,0 +1,153 @@
+
+#undef NDEBUG
+
+#include "benchmark/benchmark.h"
+#include "output_test.h"
+
+// ========================================================================= //
+// ------------------------ Thousands Customisation ------------------------ //
+// ========================================================================= //
+
+void BM_Counters_Thousands(benchmark::State& state) {
+  for (auto _ : state) {
+  }
+  namespace bm = benchmark;
+  state.counters.insert({
+      {"t0_1000000DefaultBase",
+       bm::Counter(1000 * 1000, bm::Counter::kDefaults)},
+      {"t1_1000000Base1000", bm::Counter(1000 * 1000, bm::Counter::kDefaults,
+                                         benchmark::Counter::OneK::kIs1000)},
+      {"t2_1000000Base1024", bm::Counter(1000 * 1000, bm::Counter::kDefaults,
+                                         benchmark::Counter::OneK::kIs1024)},
+      {"t3_1048576Base1000", bm::Counter(1024 * 1024, bm::Counter::kDefaults,
+                                         benchmark::Counter::OneK::kIs1000)},
+      {"t4_1048576Base1024", bm::Counter(1024 * 1024, bm::Counter::kDefaults,
+                                         benchmark::Counter::OneK::kIs1024)},
+  });
+}
+BENCHMARK(BM_Counters_Thousands)->Repetitions(2);
+ADD_CASES(
+    TC_ConsoleOut,
+    {
+        {"^BM_Counters_Thousands/repeats:2 %console_report "
+         "t0_1000000DefaultBase=1000k "
+         "t1_1000000Base1000=1000k t2_1000000Base1024=976.56[23]k "
+         "t3_1048576Base1000=1048.58k t4_1048576Base1024=1024k$"},
+        {"^BM_Counters_Thousands/repeats:2 %console_report "
+         "t0_1000000DefaultBase=1000k "
+         "t1_1000000Base1000=1000k t2_1000000Base1024=976.56[23]k "
+         "t3_1048576Base1000=1048.58k t4_1048576Base1024=1024k$"},
+        {"^BM_Counters_Thousands/repeats:2_mean %console_report "
+         "t0_1000000DefaultBase=1000k t1_1000000Base1000=1000k "
+         "t2_1000000Base1024=976.56[23]k t3_1048576Base1000=1048.58k "
+         "t4_1048576Base1024=1024k$"},
+        {"^BM_Counters_Thousands/repeats:2_median %console_report "
+         "t0_1000000DefaultBase=1000k t1_1000000Base1000=1000k "
+         "t2_1000000Base1024=976.56[23]k t3_1048576Base1000=1048.58k "
+         "t4_1048576Base1024=1024k$"},
+        {"^BM_Counters_Thousands/repeats:2_stddev %console_report "
+         "t0_1000000DefaultBase=0 t1_1000000Base1000=0 t2_1000000Base1024=0 "
+         "t3_1048576Base1000=0 t4_1048576Base1024=0$"},
+    });
+ADD_CASES(TC_JSONOut,
+          {{"\"name\": \"BM_Counters_Thousands/repeats:2\",$"},
+           {"\"run_type\": \"iteration\",$", MR_Next},
+           {"\"iterations\": %int,$", MR_Next},
+           {"\"real_time\": %float,$", MR_Next},
+           {"\"cpu_time\": %float,$", MR_Next},
+           {"\"time_unit\": \"ns\",$", MR_Next},
+           {"\"t0_1000000DefaultBase\": 1\\.(0)*e\\+(0)*6,$", MR_Next},
+           {"\"t1_1000000Base1000\": 1\\.(0)*e\\+(0)*6,$", MR_Next},
+           {"\"t2_1000000Base1024\": 1\\.(0)*e\\+(0)*6,$", MR_Next},
+           {"\"t3_1048576Base1000\": 1\\.048576(0)*e\\+(0)*6,$", MR_Next},
+           {"\"t4_1048576Base1024\": 1\\.048576(0)*e\\+(0)*6$", MR_Next},
+           {"}", MR_Next}});
+ADD_CASES(TC_JSONOut,
+          {{"\"name\": \"BM_Counters_Thousands/repeats:2\",$"},
+           {"\"run_type\": \"iteration\",$", MR_Next},
+           {"\"iterations\": %int,$", MR_Next},
+           {"\"real_time\": %float,$", MR_Next},
+           {"\"cpu_time\": %float,$", MR_Next},
+           {"\"time_unit\": \"ns\",$", MR_Next},
+           {"\"t0_1000000DefaultBase\": 1\\.(0)*e\\+(0)*6,$", MR_Next},
+           {"\"t1_1000000Base1000\": 1\\.(0)*e\\+(0)*6,$", MR_Next},
+           {"\"t2_1000000Base1024\": 1\\.(0)*e\\+(0)*6,$", MR_Next},
+           {"\"t3_1048576Base1000\": 1\\.048576(0)*e\\+(0)*6,$", MR_Next},
+           {"\"t4_1048576Base1024\": 1\\.048576(0)*e\\+(0)*6$", MR_Next},
+           {"}", MR_Next}});
+ADD_CASES(TC_JSONOut,
+          {{"\"name\": \"BM_Counters_Thousands/repeats:2_mean\",$"},
+           {"\"run_type\": \"aggregate\",$", MR_Next},
+           {"\"iterations\": %int,$", MR_Next},
+           {"\"real_time\": %float,$", MR_Next},
+           {"\"cpu_time\": %float,$", MR_Next},
+           {"\"time_unit\": \"ns\",$", MR_Next},
+           {"\"t0_1000000DefaultBase\": 1\\.(0)*e\\+(0)*6,$", MR_Next},
+           {"\"t1_1000000Base1000\": 1\\.(0)*e\\+(0)*6,$", MR_Next},
+           {"\"t2_1000000Base1024\": 1\\.(0)*e\\+(0)*6,$", MR_Next},
+           {"\"t3_1048576Base1000\": 1\\.048576(0)*e\\+(0)*6,$", MR_Next},
+           {"\"t4_1048576Base1024\": 1\\.048576(0)*e\\+(0)*6$", MR_Next},
+           {"}", MR_Next}});
+ADD_CASES(TC_JSONOut,
+          {{"\"name\": \"BM_Counters_Thousands/repeats:2_median\",$"},
+           {"\"run_type\": \"aggregate\",$", MR_Next},
+           {"\"iterations\": %int,$", MR_Next},
+           {"\"real_time\": %float,$", MR_Next},
+           {"\"cpu_time\": %float,$", MR_Next},
+           {"\"time_unit\": \"ns\",$", MR_Next},
+           {"\"t0_1000000DefaultBase\": 1\\.(0)*e\\+(0)*6,$", MR_Next},
+           {"\"t1_1000000Base1000\": 1\\.(0)*e\\+(0)*6,$", MR_Next},
+           {"\"t2_1000000Base1024\": 1\\.(0)*e\\+(0)*6,$", MR_Next},
+           {"\"t3_1048576Base1000\": 1\\.048576(0)*e\\+(0)*6,$", MR_Next},
+           {"\"t4_1048576Base1024\": 1\\.048576(0)*e\\+(0)*6$", MR_Next},
+           {"}", MR_Next}});
+ADD_CASES(TC_JSONOut,
+          {{"\"name\": \"BM_Counters_Thousands/repeats:2_stddev\",$"},
+           {"\"run_type\": \"aggregate\",$", MR_Next},
+           {"\"iterations\": %int,$", MR_Next},
+           {"\"real_time\": %float,$", MR_Next},
+           {"\"cpu_time\": %float,$", MR_Next},
+           {"\"time_unit\": \"ns\",$", MR_Next},
+           {"\"t0_1000000DefaultBase\": 0\\.(0)*e\\+(0)*,$", MR_Next},
+           {"\"t1_1000000Base1000\": 0\\.(0)*e\\+(0)*,$", MR_Next},
+           {"\"t2_1000000Base1024\": 0\\.(0)*e\\+(0)*,$", MR_Next},
+           {"\"t3_1048576Base1000\": 0\\.(0)*e\\+(0)*,$", MR_Next},
+           {"\"t4_1048576Base1024\": 0\\.(0)*e\\+(0)*$", MR_Next},
+           {"}", MR_Next}});
+
+ADD_CASES(
+    TC_CSVOut,
+    {{"^\"BM_Counters_Thousands/"
+      "repeats:2\",%csv_report,1e\\+(0)*6,1e\\+(0)*6,1e\\+(0)*6,1\\.04858e\\+("
+      "0)*6,1\\.04858e\\+(0)*6$"},
+     {"^\"BM_Counters_Thousands/"
+      "repeats:2\",%csv_report,1e\\+(0)*6,1e\\+(0)*6,1e\\+(0)*6,1\\.04858e\\+("
+      "0)*6,1\\.04858e\\+(0)*6$"},
+     {"^\"BM_Counters_Thousands/"
+      "repeats:2_mean\",%csv_report,1e\\+(0)*6,1e\\+(0)*6,1e\\+(0)*6,1\\."
+      "04858e\\+(0)*6,1\\.04858e\\+(0)*6$"},
+     {"^\"BM_Counters_Thousands/"
+      "repeats:2_median\",%csv_report,1e\\+(0)*6,1e\\+(0)*6,1e\\+(0)*6,1\\."
+      "04858e\\+(0)*6,1\\.04858e\\+(0)*6$"},
+     {"^\"BM_Counters_Thousands/repeats:2_stddev\",%csv_report,0,0,0,0,0$"}});
+// VS2013 does not allow this function to be passed as a lambda argument
+// to CHECK_BENCHMARK_RESULTS()
+void CheckThousands(Results const& e) {
+  if (e.name != "BM_Counters_Thousands/repeats:2")
+    return;  // Do not check the aggregates!
+
+  // check that the values are within 0.01% of the expected values
+  CHECK_FLOAT_COUNTER_VALUE(e, "t0_1000000DefaultBase", EQ, 1000 * 1000,
+                            0.0001);
+  CHECK_FLOAT_COUNTER_VALUE(e, "t1_1000000Base1000", EQ, 1000 * 1000, 0.0001);
+  CHECK_FLOAT_COUNTER_VALUE(e, "t2_1000000Base1024", EQ, 1000 * 1000, 0.0001);
+  CHECK_FLOAT_COUNTER_VALUE(e, "t3_1048576Base1000", EQ, 1024 * 1024, 0.0001);
+  CHECK_FLOAT_COUNTER_VALUE(e, "t4_1048576Base1024", EQ, 1024 * 1024, 0.0001);
+}
+CHECK_BENCHMARK_RESULTS("BM_Counters_Thousands", &CheckThousands);
+
+// ========================================================================= //
+// --------------------------- TEST CASES END ------------------------------ //
+// ========================================================================= //
+
+int main(int argc, char* argv[]) { RunOutputTests(argc, argv); }